All of Zambia, it seems—from the army to the Boy Scouts to local theater troupes—has been mobilized to stop malaria. In 1985, the nation's malaria-control budget was 30 thousand dollars. Now, supported with international grant money, it's more than 40 million. Posters have been hung throughout the country, informing people of malaria's causes and symptoms and stressing the importance of medical intervention. (The vast majority of the nation's malaria cases are never treated by professionals.) There are even Boy Scout merit badges for knowledge about malaria. Zambia's plan is to educate the public, then beat the disease through a three-pronged assault: drugs, sprays, and mosquito nets.

The country has dedicated itself to dispensing the newest malaria cure, which also happens to be based on one of the oldest—an herbal medicine derived from a weed related to sagebrush, sweet wormwood, called artemisia. This treatment was first described in a Chinese medical text written in the fourth century A.D. but seems to have been overlooked by the rest of the world until now. The new version, artemisinin, is as powerful as quinine with few of the side effects. It's the last remaining surefire malaria cure. Other drugs can still play a role in treatment, but the parasites have developed resistance to all of them, including quinine itself. To help reduce the odds that a mutation will also disarm artemisinin, derivatives of the drug are mixed with other compounds in an antimalarial barrage known as artemisinin-based combination therapy, or ACT.

Zambia is also purchasing enough insecticide to spray every house in several of the most malarious areas every year, just before the rainy season. It has already returned to DDT—though just for indoor use, in controlled quantities. In the face of the growing malaria toll, access to DDT is gradually becoming easier, and even the Sierra Club does not oppose limited spraying for malaria control. Finally, the Zambian government is distributing insecticide-treated bed nets to ward off mosquitoes during the night, when the malaria-carrying Anopheles almost always bite.

The plan sounds straightforward, but progress against malaria never comes easily. Many Zambians living far from hospitals depend on roadside stalls for medicines. There, ACTs can cost more than a dollar a dose—virtually unaffordable in a country where more than 70 percent of the population survives on less than a dollar a day. So people buy other drugs, for as little as 15 cents. They provide temporary relief, reducing the malarial fever, but may do little to halt the parasites.

Then there are widespread traditional beliefs. One of the posters plastered across Zambia reads: "Malaria is not transmitted by witchcraft, drinking dirty water, getting soaked in rain, or chewing immature sugarcane." When children suffer from seizures—a symptom of advanced cerebral malaria—some parents interpret it as a hex and head straight to a traditional healer. By the time they make it to the hospital, it's too late.

Even the gift of a bed net can backfire. There's no question that the nets can save lives, especially the latest types, which are impregnated with insecticide. But first they need to reach the people most in need, and then they must be properly used. "Distributing nets to remote villages is a nightmare," says Malama Muleba, executive director of the nonprofit Zambia Malaria Foundation. "It's one thing for me to convince Bill and Melinda Gates to donate money, it's quite another to actually get the nets out."

The Zambian army has been employed to help, but even after delivery, people can be reluctant to sleep beneath nets, which make a hot and stuffy part of the world feel hotter and stuffier. If a leg pops out at night or the fabric is torn, mosquitoes can still reach the skin. And the nets are sometimes misused, as fishing gear. Theater troupes are spreading out into the Zambian countryside, emphasizing the proper use of bed nets through stage productions in settlements large and small.

Despite the difficulties, Zambia's campaign has started to produce results. In 2000, a study showed that fewer than 2 percent of children under the age of five slept under an insecticide-treated bed net. Six years later, the number had risen to 23 percent. The government of Zambia says an ACT known as Coartem is now available cost free to the entire population. In a country that was steadily losing 50,000 children a year to malaria, early indications are that the death rate has already been reduced by more than a third.

But what if donor money dries up? What if Zambia's economy collapses? What about political instability? Both Angola and the Democratic Republic of the Congo, which flank Zambia, have a history of war. In the 1970s, during a civil war in Angola, six bombs landed near Kalene Mission Hospital; in the Congo war years, some of the nearby roads were mined.

"This is a critical moment," says Kent Campbell, program director of the Malaria Control and Evaluation Partnership in Africa. "There are no national models of success with malaria control in Africa. None. All we've seen is pessimism and failure. If Zambia is a success, it will have a domino effect. If it's a failure, donors will be discouraged and move on, and the problem will continue to get worse."

No matter how much time, money, and energy are expended on the effort, there still remains the most implacable of foes—biology itself. ACTs are potent, but malaria experts fear that resistance may eventually develop, depriving doctors of their best tool. Before the ban on DDT, there were already scattered reports of Anopheles mosquitoes resistant to the insecticide; with its return, there are sure to be more. Meanwhile, global warming may be allowing the insects to colonize higher altitudes and farther latitudes.

Drugs, sprays, and nets, it appears, will never be more than part of the solution. What's required is an even more decisive weapon. "When I look at the whole malaria situation," says Louis Miller, co-chief of the malaria unit at the National Institute of Allergy and Infectious Diseases, "it all seems to come down to one basic idea: We sure need a vaccine."